Hydroxyapatite as a filler for biosynthetic PHB homopolymer and P(HB–HV) copolymers

This paper deals with some of the fundamental problems encountered when using a semicrystalline polymer as the matrix phase for a particulate‐filled composite. As our model system we adopted poly‐(R)‐3‐hydroxybutyrate, PHB, and two copolymers of (R)‐3‐hydroxybutyrate and (R)‐3‐hydroxyvalerate, P(HB–HV), for the matrix phase, and the mineral calcium hydroxyapatite as a particulate filler. The structure and properties of compression‐moulded films of various compositions were investigated by polarized light microscopy, wide‐angle X‐ray scattering and mechanical testing. It was found that the degree of crystallinity of the matrix was lower in filled samples, and that the spherulitic crystallization of the matrix appeared to cause the filler particles to form agglomerates, which would not be as effective a reinforcement as finely dispersed primary filler particles. The tensile strength, strain‐to‐break and tensile modulus of samples of different compositions were analysed using well‐known theories for composite behaviour. Copyright © 2003 Society of Chemical Industry     

络合剂在优化纺织品湿加工整理中的应用

新型络合剂在多种工序中的应用,可以为单道工序甚至整个生产过程节约大量成本,加速生产循环,省去部分加工步骤,同时还提高了不稳定配方的生产可靠性.极简化的操作水平也可以节约大量能源.现代技术和设计应将络合剂作为重要的过程控制参数,因为这关系到整个工艺的成败.     

On the mechanism of reforming reactions in the presence of H-erionite. A C tracer study

Pt---Al₁O₃ reforming catalysts containing H-erionite were tested by means of the reaction of 2-¹³C-heptane. The ¹³C enrichment in each position of the toluene formed was measured using NMR spectroscopy. It was found that aromatization proceeds via both 1,6 and 1,5 ring closures. In the presence of H-erionite, the origional tracer atom positions in the ring are changed by secondary methyl shifts. Isomerisation reactions of the n-heptane are responsible for the small but significant labelling of the methyl group.     

Mantle-cell lymphomas have more widespread disease and a slower response to chemotherapy compared with follicle-center lymphomas: results of a prospective comparative analysis of the German Low-Grade Lymphoma Study Group

PURPOSE: To compare mantle-cell lymphomas (MCLs) and follicle-center lymphomas (FCLs) for their features of clinical presentation, response to chemotherapy, and prognosis on the basis of a prospective randomized clinical trial. PATIENTS AND METHODS: Patients with MCL and FCL who entered onto the prospective randomized comparison of cyclophosphamide, vincristine, and prednisone (COP) versus prednimustine and mitoxantrone (PmM) followed by a second randomization for interferon (IFN) maintenance versus observation only. RESULTS: One hundred sixty-five of 234 patients had FCL and 45 of 234 patients had MCL. With FCL, both sexes were equally affected (men, 47%); patients with MCL were predominantly men (78%; P < .0004) and had a higher median age (64 v 53 years; P < .0001). Patients with MCL also had more widespread disease, reflected by the proportion of patients with two or greater extranodal manifestations (43% v 21%; P < .005) and nine or greater involved nodal areas (64% v 45%; nonsignificant [NS]). Response to chemotherapy was significantly lower in patients with MCL (complete remission [CR] + partial remission [PR], 69% v 88%; P < .05) and occurred at a slower pace. Patients with MCL also had a shorter event-free interval (median, 8 v 24 months; P < .0001) and overall survival (median, 28 v 77 months; P < .0001). In both subtypes, however, patients with less than two residual lymphoma manifestations in remission experienced a relatively good prognosis with an estimated 5-year survival of greater than 60% for MCL and greater than 75% for FCL. CONCLUSION: MCL and FCL differ substantially in their features of presentation, response to chemotherapy, and long-term prognosis. The extent of residual disease after completion of chemotherapy discriminates patients with different prognosis and may be used for the stratification of postremission strategies.     

Programmable vision processor/controller for flexibleimplementation of current and future image compression standards

The vision processor (VP) and vision controller (VC), two integrated products dedicated to video compression, are discussed. The chips implement the P×64, JPEG, and MPEG image compression standards. The VP forms the heart of the image compression system. It performs discrete cosine transform (DCT), quantization, and motion estimation, as well as inverse DCT, and inverse quantization. The highly parallel and microcode-based processor performs all of the JPEG, MPEG, and P×64 algorithms. The VC smart microcontroller controls the compression process and provides the interface to the host system. It captures pixels from a video source, performs video preprocessing, supervises pixel compression by the VP, performs Huffman encoding, and passes the compressed data to the host over a buffered interface. It takes compressed data from the host, performs coder decoding, supervises decompression via the VP, performs postprocessing, and generates digital pixel output for a video destination such as a monitor     

A novel extraction method for peanut allergenic proteins in chocolate and their detection by a liposome-based lateral flow assay

In this study, conditions for extracting the major peanut allergen (Ara h1) from chocolate were optimized, and the extracted samples were analyzed by a lateral flow assay (LFA) using liposomal nanovesicles. The optimal conditions using peanut-spiked chocolate were found to be extraction with a mixture of phosphate buffered saline and hexane for 30 min at 35 °C. After centrifugation, the buffer portion was treated with insoluble poly(vinylpolypyrrolidone) to remove phenolic compounds, and then analyzed by the LFA. The entire analysis, including sample preparation and LFA, could be easily completed within 2 h, and the detection limit was 158 g of peanuts/g of chocolate.     

Is there a future for antioxidants in atherogenesis?

Antioxidants, preferentially those of dietary origin, have for a long time been considered to help against diseases that are presumably aggravated by oxidative stress, such as cardiovascular diseases, cancer, and neurodegenerative disorders. The outcome of clinical trials undertaken to corroborate this hypothesis, however, remained largely inconclusive. Evidence is now emerging that some dietary "antioxidants" influence signaling pathways and the expression of genes relevant in atherosclerosis by mechanisms other than antioxidative ones. By concrete examples we show that (1) vitamin E has gene regulatory functions which might be more important than acting as an antioxidant in vivo, (2) selenium itself is not an antioxidant at all, and even not in general when incorporated into glutathione peroxidases, and (3) a moderate oxidative stress is beneficial rather than detrimental since it can induce defense mechanisms counteracting xenobiotic and oxidative stress. Thus, there is only a future for antioxidants in the prevention of any disease if their real mechanism of action is considered and suitable read-outs and biomarkers are established.